Abstract Uni-axial tensile deformation of LA41 magnesium alloy has been carried out and PLC phenomenon, also known as serrated flow or plastic instability, is observed. This kind of alloy exhibits negative strain rate sensitivity (SRS) at room temperature, that is, SRS is negative throughout the strain rate range from 3.33×10-4 s-1 to 6.66×10-3 s-1 at ambient temperature. Both ultimate stress and 0.2% proof stress decrease with increasing strain rate, whilst critical strain of serrated flow is found to rise with enhanced strain rate. A new explanation for this unusual phenomenon is presented. The model of dynamic strain aging (DSA) is established though thorough discussion.
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